SUDA: A Dust Mass Spectrometer for Compositional Surface Mapping for a Mission to Europa

Abstract : We developed a dust mass spectrometer to measure the composition of ballistic dust particles populating the thin exospheres that were detected around each of the Galilean moons. Since these grains are direct samples from the moons' icy surfaces, unique composition data will be obtained that will help to define and constrain the geological activities on and below the moons? surface. The proposed instrument will make a vital contribution to NASA's planned Europa Clipper mission and provide key answers to its main scientific questions about the surface composition, habitability, the icy crust, and exchange processes with the deeper interior of the Jovian icy moon Europa. The SUrface Dust Aanalyser (SUDA) is a time-of-flight, reflectron-type impact mass spectrometer, opti-mised for a high mass resolution which only weakly depends on the impact location. The small size (268 × 250×171 mm 3), low mass (< 4 kg) and large sensitive area (220 cm 2) makes the instrument well suited for the challenging demands of the Europa Clipper mission. A full-size prototype SUDA instrument was built in order to demonstrate its performance through calibration experiments at the dust accelerator at NASA's IMPACT institute at Boulder, CO with a variety of cos-mochemically relevant dust analogues. The effective mass resolution of m/∆m of 200-250 is achieved for mass range of interest m = 1-250.